The present invention pertains to new compounds which are 2-oxy derivatives of 5-isopropylidene-7-hydroxy- 9-substituted-2,6-methano-3,4,5,6-tetrahydro-2H-1-benzoxocins. Certain benzoxocin derivatives are known in the art. 2-Methyl-5-isopropenyl-7-hydroxy-9-n-pentyl-2,6-methano- 3,4,5,6-tetrahydro-2H-1-benzoxocin has been prepared by reaction of boron trifluoride etherate with 2-(3-methyl- 6-isopropenyl-2-cyclohexenyl)-5-n-pentylresorcinol, commonly referred to as cannabidiol; see Gaoni and Mechoulam, Tetrahedron, 22, 1481 (1966), and J. Am. Chem. Soc., 93, 217 (1971). Razdan and Zitko reported that the above named isopropenyl benzoxocin derivative can be converted to the corresponding isopropylidene benzoxocin derivative by reaction with p-toluenesulfonic acid. These authors additionally suggested that 2-methyl-5-isopropylidene-7-hydroxy-9-n-pentyl-2,6-methano-3,4,5,6-tetrahy dro-2H-1-benzoxocin can be converted to 1-hydroxy-3-n-pentyl-6,6,9-trimethyl-6a 7,8,10a-tetrahydrodibenzo pyran under acidic conditions; see Tetrahedron Letters, No. 56, 4947 (1969). Recently, Razdan et al. reported the preparation of 2-methyl-5-isopropylidene- 7-hydroxy-9-n-pentyl-2,6-methano-3,4,5,6-tetrahydro-2H-1-benzoxocin by reaction of 5-n-pentylresorcinol with 1-hydroxy-1-methyl-4-isopropenyl-2-cyclohexene; J. Am. Chem. Soc., 96, 5860 (1974).
All of the above-mentioned benzoxocin derivatives bear a 2-methyl substituent. Such compounds can provide, upon rearrangement, dibenzo[b,d]pyrans having a 9-methyl group. No benzoxocin derivative have hitherto been known which could be rearranged to provide a dibenzo[ b,d]pyran- 9-one, because the requisite benzoxocin requires an oxo substituent at the 2-position and not a methyl group, and such 2-oxo compounds have not previously been available. Certain dibenzo[ b,d]pyran-9-ones preparable from 2-oxobenzoxocin derivatives are of particular importance as anti-depressant and anti-anxiety drugs, as described in U.S. Pat. Nos. 3,928,598; 3,944,673; and 3,953,603. It is therefore an object of this invention to provide 2-oxy-5-isopropylidene-7-hydroxy-9-substituted-2,6-methano-3,4,5,6-tetrahy dro-2H-1-benzoxocins which can be converted to useful dibenzo[ b,d]pyran- 9-ones.